1. Field of the Invention
This invention relates to a method of reading service information in a video-communication receiver provided with means for receiving and deciphering ciphered signals transmitted to the receiver by a television transmitter, said means particularly comprising a microprocessor associated with a random-access memory and a read-only memory containing instructions, and a deciphering module for deciphering said ciphered signals, in which method ciphered information is introduced into the receiver in a service mode.
The invention also relates to a video-communication receiver comprising means for receiving and deciphering ciphered signals transmitted to the receiver by a television transmitter, and which may include e-mail and facsimile messages, etc., said means particularly comprising a microprocessor associated with a random-access memory and a read-only memory containing instructions, and a deciphering module for deciphering said ciphered signals.
The invention also relates to a microprocessor card intended for a receiver according to the invention.
2. Description of the Related Art
A television system in which the pictures are descrambled is known from Patent Application WO 93/07715 (Thomson). In accordance with this document, a specific microprocessor card is used by an installer for automatically updating the television channels in a receiver in accordance with the reception range.
Such an update of a receiver may concern the reception frequencies, but also data authenticating the user's subscription. It is therefore useful that the servicing information, or at least certain information, is ciphered to secure it from abuse. In principle, it is thus necessary to use a deciphering module which supplies deciphered data via ciphered service information on the basis of a secret code and/or deciphering instructions applied thereto. The deciphering instructions themselves may also be ciphered.